Home
NCERT Soltions
Class 11
Biology
Excretory products and their Elimination
Give a brief account of the counter current mechanism.

Give a brief account of the counter curr | Class 11 Biology Chapter Excretory products and their Elimination, Excretory products and their Elimination NCERT Solutions

Welcome to the NCERT Solutions for Class 11 Biology - Chapter Excretory products and their Elimination. This page offers a step-by-step solution to the specific question from Exercise 1, Question 4: . With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.

Question 4: Give a brief account of the counter current mechanism.

Answer:

The counter current mechanism operating inside the kidney is the main adaptation for the conservation of water. There are two counter current mechanisms inside the kidneys. They are Henle’s loop and vasa rectae.

Henle’s loop is a U-shaped part of the nephron. Blood flows in the two limbs of the tube in opposite directions and this gives rise to counter currents. The Vasa recta is an efferent arteriole, which forms a capillary network around the tubules inside the renal medulla. It runs parallel to Henley’s loop and is U-shaped. Blood flows in opposite directions in the two limbs of vasa recta. As a result, blood entering the renal medulla in the descending limb comes in close contact with the outgoing blood in the ascending limb.

Vasa Recaae & Henle's Loop

The osmolarity increases from 300 mOsmolL ^-1 in the cortex to 1200 mOsmolL ^-1in the inner medulla by counter current mechanism. It helps in maintaining the concentration gradient, which in turn helps in easy movement of water from collecting tubules. The gradient is a result of the movement of NaCl and urea.

Other Questions of Chapter Excretory products and their Elimination

Aquatic animals generally are ammonotelic in nature where as terrestual forms are not. Comment.

Q: Match the items of column I with those of column II:
Column I Column II
(a) Ammonotelism (i) Birds
(b) Bowmans capsule (ii) Water reabsorption
(c) Micturition (iii) Bony fish
(d) Uricotelism (iv) Urinary bladder
(e) ADH (v) Renal tubule

Q: What is the significance of juxtaglomerular apparatus (JGA) in kidney function?

Q: Terrestrial animals are generally either ureotelic or uricotelic, not ammonotelic, why?

Q: Indicate whether the following statements are true or false:
(a) Micturition is carried out by a reflex.
(b) ADH helps in water elimination, making the urine hypotonic.
(c) Protein-free fluid is filtered from blood plasma into the Bowmans capsule.
(d) Henles loop plays an important role in concentrating the urine.
(e) Glucose is actively reabsorbed in the proximal convoluted tubule.

Describe the role of liver, lungs and skin in excretion.

Q: Fill in the gaps:
(a) Ascending limb of Henles loop is ____________to water whereas the descending limb is___________to it.
(b) Reabsorption of water from distal parts of the tubules is facilitated by hormone____________.
(c) Dialysis fluid contains all the constituents as in plasma except ________.
(d) A healthy adult human excretes (on an average) _______ gm of urea/day.

Q: Name the following:
(a) A chordate animal having flame cells as excretory structures
(b) Cortical portions projecting between the medullary pyramids in the human kidney
(c) A loop of capillary running parallel to the Henles loop.

What is the procedure advised for the correction of extreme renal failure? Give a brief account of it.

Q: Explain the autoregulatory mechanism of GFR.

Popular questions of class 11 Biology

Q: Describe briefly the four major groups of Protozoa.

Q: Why are living organisms classified?

Q: State two economically important uses of: (a) Heterotrophic bacteria (b) Archaebacteria

Q: What is the difference between direct and indirect development?

Define a taxon. Give some examples of taxa at different hierarchical levels.

Q: Describe the important properties of enzymes.

What are the steps involved in formation of a root nodule?

Q: Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal.

Q: How is a key helpful in the identification and classification of an organism?

Q: What is stomatal apparatus? Explain the structure of stomata with a labelled diagram.

Recently Viewed Questions of Class 11 Biology

Name the pathological condition when uncontrolled cell division occurs.

Name the cells/tissues in human body which
a. exhibit ameboid movement
b. exhibit ciliary movement

Q: How is the study of plant anatomy useful to us?

How do you distinguish between a skeletal muscle and a cardiac muscle?

Q: Explain the term thecodont and diphyodont.

Why earthworm is called the friend of farmer?

Q: Draw the labelled diagram of the following:
(i) Gram seed
(ii) V.S. of maize seed

Which of the following is correct:
(a) Cells of all living organisms have a nucleus.
(b) Both animal and plant cells have a well defined cell wall.
(c) In prokaryotes, there are no membrane bound organelles.
(d) Cells are formed de novo from abiotic materials.

Mitosis results in producing two cells which are similar to each other. What would be the consequence if each of the following irregularities
occur during mitosis?
a. Nuclear membrane fails to disintegrate
b. Duplication of DNA does not occur
c. Centromeres do not divide
d. Cytokinesis does not occur.

Q: Discuss with your teacher about
(i) haploid insects and lower plants where cell-division occurs, and
(ii) some haploid cells in higher plants where cell-division does not occur.

Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

Read the question carefully and focus on the core concept being asked.
Reference examples and data from the chapter when answering questions about Excretory products and their Elimination.
Review previous year question papers to get an idea of how such questions may be framed in exams.
Practice answering questions within the time limit to improve your speed and accuracy.
Discuss your answers with your teachers or peers to get feedback and improve your understanding.

Latest Blog Posts

Stay updated with our latest educational content and study tips

The Hidden Risks of Online Gaming for Children — Is your child safe while gaming online?

Online gaming has rapidly become one of the most popular pastimes among children. Whether it’s multiplayer mobile games , PC adventures or console challenges , kids are spending more time than ever in the virtual world . On the surface, gaming seems entertaining and even educational – improving hand- eye coordination , teamwork and problem […]

The Role of Parents in Digital Literacy – Guiding Kids for a Smarter Online Future

Kids today are surrounded by screens from the moment they wake up . Whether it’s smart classrooms, online lessons or video games with friends technology has quietly become a part of everything they do. It’s amazing how much they can learn, explore and create with just a tap or a click. But it also brings […]

How to Recognize and Prevent Online Scams Targeting Kids

The internet is full of entertaining apps, games and movies for kids of all ages. However not everything online is safe. Hidden among these entertaining platforms are internet frauds that target children with phony gifts, free game currencies or friendly looking people. As a parent, you may believe that scammers only target adults; yet children […]

How to Talk to Kids About Screen Time rules Without Conflict

Did you know? The average teenager spends 7 – 8 hours daily on screens . That’s almost like working a full – time job in front of a screen – except kids aren’t earning a paycheck; instead they’re often trading sleep, focus and health for digital time. In today’s world, screens are everywhere – TV, […]

View All Blog Posts

Comments

Shafi
Feb 11, 2019

Thnx

Vani
Feb 10, 2019

Vaishnavi
Jan 29, 2019

Apt answer for the question . Thank you.ð

vidd
Jan 02, 2019

very specific answers.....nice!!!!1

Sania Krish
Dec 04, 2018

I just freaking love this site. It gives the apt answers. No exaggeration. Answer to the question. Best for clearing doubts.

paul
Nov 02, 2018

specific n excellent

Roop Molakala
Jul 27, 2018

Easy to learn

Amal
Mar 15, 2018

Specifically given answers

Tiffany
Feb 15, 2018

nice mate!

Anisha
Feb 11, 2018

excellent